Illuminated directory



Aug. 30, 1955 w. A. sPlr-:LMANN ET AL 2,716,298

ILLUMINATED DIRECTORY Filed Sept. l5, 1951 V//l ll United States Patent ILLUMINATED DIRECTORY Willson A. Spielmann, Winnetka, yand George W. Hughes, Highland Park, Ill., assignors -to The Tablet =& Ticket Company, Chicago, Ill., a corporation .of -Illinois ApplicationSeptember 15, 1`951,Serial No. 246,732

6 Claims. (Cl. 411-132) This invention `relates l'generally to Ailluminated directory panels and more particularly to a `novel `building directory having identication strips -with appropriate contrasting markings or characters clamped between -a transparent Iface panel and an relectro-luminescent capaci- 1tor whereby the strips `will be silhouetted against a luminous `background to improve the -visibility of the identitication markings or characters.

According to the general features o'f the present Ainvention, a `directory panel is provided with Ya rectangular frame including grooved side railsand 4end rails `removably xed thereto and extending therebetween. Atransparent face panel `extends across the frame and is 1received in the `grooves of the iside rails. Theend `rails are positioned to retain the transparent panel in `assembly with the iframe. A selected plurality of identification strips are `disposed on the panel land lexltend across the iframe. The strips are lconstructed to provide contrasting opaque and ilight transmitting `areas forming markings or characters. A luminescent condenser rpanel forming 'an electroduminescent :capacitor fand :coextensive -`in area :with the transparent panel iis resilliently clamped `into 1assembly adjacent the strips Eby iresilient :clamping 4means `carried on itheiframe `sofas to silhouette the-characters of the strips against a uniform luminous background.

It is an robject of the Ip'resen't invention to `provide an improved illuminated directory which is particularly compact and by means of which ia uniformly .luminous background may 'be provided "to silhouette characters or markingsformed on a selected 'plurality of replaceable strips.

Another object of the present invention is "to provide an illuminated directory having improved light source means associated therewith to provide a luminous background for indicia strips having markings formed thereon. r

Yet another object of the present invention is to provide an illuminated building directory having improved visibility characteristics and which is particularly economical in operation.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheet of drawings in which a preferred structural ernbodiment of an illuminated directory incorporating the principles of the present invention is shown by Way of illustrative example.

On the drawings:

Figure l is a broken front elevational view of a building directory provided in accordance with the principles of the present invention.

Figure 2 is a broken rear elevational view of a building directory provided in accordance with the principles of the present invention;

Figure 3 is a broken somewhat diagrammatic crosssectional view of the building directory shown in Figures 1 and 2;

ICC

Figure 4 is an enlarged fragmentary cross-sectional View, somewhat diagrammatic, showing :additional details of construction of the building directory according to the present invention; and

Figure `5 is a diagrammatic View of a portion of an `electro-luminescent capacitor provided in accordance with the principles of the present invention.

As shown on the drawings:

An illuminated directory is indicated generally by the reference numeral 10 and comprises a substantially rectangular frame including a pair of oppositely disposed side rails 11 which are of generally L-shaped configuration and which are provided with a longitudinal groove 12 extending from end to end thereof. The frame further includes a pair of oppositely disposed end rails '13 which are removably xed to the side rails 11 by a plurality of fasteners 14. The end rails 13 are also generally L shaped, thereby to provide a shelf 13a seating a transparent panel 16 which extends across `the frame and into the grooves 12 of the side rails 11.

A plurality of strips 17 are provided to form indicia means for the illuminated directory 1th. In .this illustrative embodiment, each of the strips 17 are translucent and have opaque characters 18 formed thereon facing the transparent panel 16. The strips 17 extend across the iframe and are substantially coextensive in width with the transparent panel 16 and are arranged to .have their end portions extend into the grooves 12 ofthe side rail 11.

Adjacent the strips 17 is provided an electro-luminescent capacitor indicated generally by the reference numeral 19. The capacitor 19 comprises a pane 20 `of electrically Anon-conductive translucent material such `as glass which `is coated on one face with a layer of electrically conductive material, for example, a thin coating offtin may be employed which `is suliiciently thin to be translucent. The translucent layer of electrically conductive `material `is shown in greatly enlarged form in the drawings and is identified bythe reference numeral 21.

A` coating of a suitable luminescent material is spread `uniformly `over Athe `conducting surface formed by `the layer`21 soas `to forma dielectric layer for Ithe capacitor, for example, `a film of phosphor suspended in a suitable 4sclid "isindicated at 22. The surface of the luminescent dielectric -lilrn 22 -is further coated `with a thin `layer of a metallic electrically `conductive material such as vai -p'orized aluminum, foil, or a dashed metallic coating,

the iilmof'conduet-ive material being "indicated at "25.

Electrical connections are made with the capacitor 19 by alixing a contact strip 24 along one edge of the pane 20, thereby to establish electrical contact with the lm 21 and contact is also established with the lm 23 at any convenient spot as for example, at 26. To prevent short circuiting, a channel-shaped piece of insulation shown at 25 is provided along the edge portions: of the pane 20 between the capacitor 19 and the side and end rails of the frame.

Retaining means are provided to hold the capacitor 19 in assembly with the directory structure, thereby to provide an arrangement which is somewhat laminar in character, the strips 17 being clamped against the transparent panel 16 by the capacitor 19. In the preferred structural embodiment herein set forth by way of illustrative example only, the retaining means takes: the form of a pair of spaced apart studs 27 which are aixed to one of the end rails 13 and which are arranged tio retain a backing member 28 received in abutting assembly with the capacitor 19.

The opposite end rail 13 is provided with an arcuate slot 29 seating a resilient spring arm Stil pivotally connected to the backing member 28 by means of a pivot pin 31.

The backing member 28 is preferably substantially coextensive with the capacitor 19 so that an evenly distributed continuous biasing force will be imparted to the capacitor 19 by the spring arm 30, thereby holding the strips 17 firmly and uniformly against the transparent panel 16 and facilitating the retention thereof in iirm assembly within the directory structure,

Suitable electrical connections may be provided to g establish an electrical iield across the elements of the capacitor 19, a conductor wire being indicated at 32 and having a plug 33 on the end thereof for connection to a suitable source of alternating current.

Upon energization of the capacitor 19, the luminescent lm 22 Will be excited by the electric iield and Will emit light as long as the exciting eld is maintained in accordance with the principles of electro-luminescence. There is thus provided a surface area of light behind the translucent strips 17 which effectively silhouettes the opaque characters 18 and which thereby improves the visibility characteristics thereof.

Although various minor structural variations might be suggested to those versed in the art, it should be understood that we wish to embody within the scope of this invention all such modifications as reasonably and properly come within the scope of our contribution to the art.

We claim as our invention:

l. In a directory panel, a rectangular frame, a transparent panel extending across the front of said frame, strips disposed on said panel, said strips having areas of contrasting light transmitting properties to form identiication characters, a second panel member across the back of said frame and clamping said strips against the transparent panel, a translucent layer of electrically conductive material on one face of said second panel and facing said strips, said second panel further including a layer of luminescent material over said electrically conductive material, and a layer of electrically conductive material on said luminescent material, and means establishing an excitation eld cross said layers of said second panel to electrically excite said luminescent material, thereby to silhouette said strips through said transparent panel against said second panel.

2. In a directory panel, a laminated panel unit comprising a pair of coextensive rectangular panels having a rectangular coextensive sheet of translucent material therebetween, one of said panels being transparent, opaque areas on said sheet of material, whereby identification characters are provided, said other panel comprising an electro-luminescent panel having a translucent coating of electrically conductive material, a coating of luminescent dielectric material, and a coating of an electrically conductive metal, and a frame mounting each of said panels and said sheet of material in aligned laminar assembly, whereby said sheet of material will be silhouetted through the transparent panel and against said electro-luminescent panel.

3. In a directory panel as defined in claim 2, said frame having a ange abutting against the margins of the transparent panel and having resilient clamping means abutting against the other panel to evenly distribute a continuous biasing force for clamping said sheet of material between said panels resiliently.

4. In a directory panel, a frame receiving a plurality of spaced strips providing a continuous directory panel face, each of said strips having areas of contrasting light transmitting properties forming identification characters, a luminescent condenser panel in said frame coextensive in area with said panel face and abutting against said strips, an electrical means energizing said luminescent condenser panel to silhouette the entire directory panel face provided by a uniformly diiused luminous background provided by said condenser panel.

5. In a directory panel as dened in claim 4, continuous bias exerting means between said condenser panel and said frame pressing said condenser panel with even pressure against said strips.

6. A directory panel comprising, a rectangular frame having grooved side rails and end rails removably ixed thereto and extending therebetween, a transparent pane extending across said face and into said grooves and being held therein by said end rails, a luminescent condenser panel in said frame substantially coextensive with said transparent pane to establish a uniformly diffused luminous backing surface, a plurality of strips clamped between said pane and said condenser panel and providing a continuous directory panel face visible Vthrough said pane against said backing surface, each of said strips having areas of contrasting light transmitting properties to form identification characters, and electrical means to electrically excite said luminescent condenser panel to silhouette said directory panel face through said transparent pane against said backing surface of said condenser panel.

References Cited in the tile of this patent UNITED STATES PATENTS 454,424 Buxton June 16, 1891 1,504,826 Larsen Aug. 12, 1924 1,840,325 McCann Ian. 12, 1932 2,566,349 Mager Sept. 4, 1951 

